1. Field of the Invention
This invention relates to a method for absorbing carbon monoxide from a gas stream. In particular, the absorbing agent is the reaction product of a Cu(I) compound and a halogenated acetylacetone.
2. Description of the Prior Art
It is well-known that cuprous salt solutions will absorb carbon monoxide (CO). A review of the early literature relating to this topic may be found in J. Appl. Chem. (London), 15, 17-28 (1965).
U.S. Pat. Nos. 3,401,112 and 3,517,079 relate to methods of separating olefins and vinyl aromatics using cuprous salts of fluoro-substituted carboxylates, fluoroborates and fluorophosphates. A process for separating CO from gas mixtures using copper (I) salts of sulfonic acids or dialkyl phosphates is disclosed in U.S. Pat. No. 4,042,669. U.S. Pat. No. 4,048,292 teaches a method for preparing high purity CO from CO.sub.2 -free gas streams using a copper ammonium C.sub.1-2 acetate as the absorbent medium.
While many Cu(I) compounds are known to form carbon monoxide-containing complexes, they suffer from one or more disadvantages such as high corrosivity, low reactivity to CO, high energy cost to regenerate CO, low selectivity to CO and instability of the absorbent system. It would be highly desirable to have a method for selectively and efficiently removing CO from a gas stream while at the same time being able to regenerate the absorbent system and recovering CO under mild conditions.